Manufacture of casein



June ,16, 1936- F. H. `cLlcKNER 2,044,282

MANUFACTURE QF-CASEIN Filed sept. 28; 1953 5 sheets-Shawl" June 16, 1936. F. H. CLICKNER MANUFACTURE oF CASEIN Filed sept. 28, 19,35

3 sheets-sheet 2 Patented .Func 16, 193.6@

Unirsel isrliarssA agossasa muomorvnn or' cham 4 Forest n. clamer. chicago, nl.. assumer to" Kraft-Phenix Cheese Corporation, Chicago,

mi., a corporation of Delaware Application september 2s, 193s, sei-m No. senseo g facture ci high-grade casein suitable for the purpose indicated.

I have found that casein, in order to be successfully used in the making of such iilms and sheets, should be substantially free from calciumsalts. All commercial caseins which I have examined and tested up to the present time, contain an objectionable percentage of calcium salts and it is diicult, if not impossible, to remove these calcium salts by'axLv process so far described in the literature without at the same time im the natural qualities of the casein.

Casein which is purchasable on the open market, is made by subjecting milk to the action of an acid. This acid may be lactic acid due to a natural souring of the milk, or it may be produced by the action of rennet upon the milk, or it may be a mineral acid, hydrochloric acid being the acid principallyemployed. The invention herein disclosed is especially adapted for use in connection with the mineral acid process.

The drawings accompanying thisapplication disclose a preferred type of apparatus or equipment by the aid of which my improved process can be emcientiy and economically practiced.

In these drawings- Fig. 1 is an elevation of the principal parts of the apparatus, certain parts being shownin sec tion.

2 is an enlarged vertical section of the acid mixing arrangement disclosed in Fis.

Fig.3isasectiontakenontheline3of Fig. 2.

Fig.4isasectiontakenonthelineS-Aiof Fig. 2. Y

Fig. 5 is an enlargement of the left-hand end of the upper conveyor and associated apparatus shown in mg. 1. l

Fig.6isasectiohtaken onthelineS-eof Fig. 5.

Fig. 7 is a section taken on the line 'l-l of Fig. 1, sind Fig. 8 is a section Fig. 2. Y v

The apparatus shown herein embodies certain features of the equipment disclosed in the M- neld Patent No. 1,716,799, and present inventaken on 'the line 8 8 of tion is in the nature of an improvement or adaptation of the process and apparatus described in v saidpatent. A

I have secured verygood results with the fol-:.1-v

lowing process.

Fresh milk as it comtes from the cows is separated so as to remove the fat or butterI but it is preferably not pasteurized as I iind that raising thetemperature of the milk to a pasteurizing temperature has a tendency to denature the pro- 10 teins and lmakes the casein sammy or sticm. This summiness or stickiness-in the casein has a tendency to'cause-conglomerization of the particles of casein which interferes with the process.

In fact, it is better throughout the process to prel5 vent the temperature of the milk from at any time exceeding 100 F. It is desirable, however, to have the temperature during the acid mixing stage as hi'sh as possible without exceeding the danger'point, otherwise, the reaction will be undesirably slow and the yield V`will be reduced.

In order to obtain the desired temperature of 110 F. without at the same time overheating any of the particles of casein, I prefer to' -use a counterfow water-iacketed arrangement which,

in eiect, is a reversed milk cooler of the pipe water-Jacket type. 'Such a heater h somewhat diagrammatically shown in the drawings by the numeral le. It consists of a central pipe il,

through which the milk is conducted to the mixing apparatus desiated as a whole l2. `Said pipe il is enclosed in a larger pipe oriachet le which receives a supply of circulating water through the feed pipe le. The water which is introduced through the pipe le is of sumcient volume. and the lengths of the pipes il and i3 in comparison with the flow .oi milk through pipe il are sumcient so that it is not necessary to use a temperature' of more than about 114 F.

for the feed water so as to raise the temperature o ofthe milkto F.bythetimeitreachesthe mixing apparatus l2. Obviously, in order to effect auch result with such a small temperature dierence, it will be necessary to circulate the feed water through pipe i4 at a rate of flow sevas eral times that of the rate of now of the milk through the pipe il. The feed water may be heated in any convenient manner and in order to save heat, it is preferably re-circulated through such heating means.

The acid tank I5 is kept supplied with commercial hydrochloric acid which has been diluted by the addition of eight times as much water. This dilute acid is conducted through a cock is and pipe i1 to the interior of a-oatlchamber-le, is

said oat chamber containing a ball float |9, which, when the ball is raised, seals the delivery orice in the dome 2| into which the pipe |1` level of acid in the acid well 2-4 Will be maintained at a uniform height.

From the acid well 24, the acid ls conducted through an adjustable valve to a downwardly directed elbow 26 which is united to the upper end 21 of the vertical mixing chamber 28'. The top wall 21 of said mixing chamber 28 has a depending nipple 29 in which there is an elongated aperture or slot 30 which communicates with the aperture and the lower\end of the elbow 26, so that the acid flows down through the center of the mixing chamber 28 in the form of a narrow, thin, ribbon-like stream.

The delivery end 3| of the milk pipe is connected into the side of the mixing chamber 28 and delivers its milk through a delivery opening 32 which is relatively narrowin height compared to its horizontal width. Immediately above the delivery opening or slot 32, there is formed in the wall of the mixing chamber 28 a downwardly directed inclined baille 33, the lower point of which extends below the center line of the slot 32, so that when the milk passing out of the slot 32 strikes the inclined lower edge of the baille 33, it

will be directed downwardly and at the proper angle to impinge upon the ribbon of acid descending from the acid delivery slot 30. Other baiiles 34 and 35 'are employed for the purpose of still further mixing up the acid and the milk. As a matter of fact, in practice I find that when the mixture of milk and acid has dropped out of the bottom of the mixing chamber 28, the reaction in a large measure is complete.

The mixture, which at thattime consists substantially of a somewhat acid whey solution containing a finely divided grain curd, drops from the mixing chamber into the head end of a flow box 36, in which there are arranged a series of alternately oppositely disposed staggered baffles as shown at 31 and 38.

From the flow box 36, the mixture or solution is delivered by a spout 40 to about the middle point of an inclined screw conveyor designated as a. whole 4|. As shown best in Fig. 5, said screw conveyor 4| comprises a continuous worm 42 in the form of a spiral ribbon, the inner edge of the spiral being spaced a substantial distance from the shaft 43 so as to provide a continuous opening 44 extending from end to end of the conveyor. The mounting of the ribbon 42 on the shaft 43 is effected by means of a series of spaced radial arms as indicated at 45, which are xedly secured in suitable bosses 46 rotating with the shaft 43. The casing 41 as to its lower half is of the proper shape and dimensions to fit closely around the worm 42. The upper end of the propeller shaft 43 is supported in a bearing 48 and is rotated by a pair of bevel gears 49 and 50, the bevel gear 50 being keyed to a shaft 5| which is driven by a chain in sprockets from the main power shaft52.

The lower end wall 53 of the screw conveyor casing and the side walls 54 thereof, are extended upwardly a substantial distance above the top of the worm at the lower end of the conveyor so as to maintain the body of liquid in the casing at such level that its upper surface extends to point between the spout 40 and the upper end of the conveyor. An overflow pipe 55 in thetop portion of the lower end wall 53 of the casing conducts the clear whey to a suitable storage tank,

not shown.

At its upper end, as shown best in Fig. 5, the lower wall of the conveyor casing 41 is cut away so as to provide a rectangular opening which delivers the grain curd into a semi-cylindrical beater chamber 56. Within said beater chamber 56, there is a pair of'bars or beaters 51 on the ends of a pair of arms 58 xed on a horizontal beater shaft 59, suitably supported co-axially in and with the cylinder 56. The shaft 59 is supported in suitable bearings and is rotated at the desired speed by a pulley 60 driven by a suitable source of power, not shown. The semi-cylinder 56 is made with a series of perforations'l providing va screen effect, so that when the material has been suiciently comminuted or disintegrated by the revolving beater arms 51, it will fall into a semi-cylindrical casing 62, forming a part of the upper end of a delivery spout orchute 63.

Above the aperture which connects the upper end of the screw conveyor 4| to the beater chamber 56, there are arranged on either side of and slightly above the conveyor shaft 43, a pair of clear water pipes 64, provided with adjustable nozzles 65 which direct sprays of clear water 66 onto the material into the beater chamber 56.

'Ihe grain curd is delivered by the spout 63 to about the middle point of a second screw conveyor 61, having substantially the same characteristics as to construction and operation as the screw conveyor 4|, except that the level of liquid in the conveyor `61 does not extend' so far up the incline. From the lower end of the conveyor 61, the wash water -is conducted to the sewer by a waste pipe 68. As the granulated curd is moved up the inclined casing of the screw conveyor 61, it is subjected to the action of a series of sprays of water 69 from a line of spray heads 10 tted in the clear water supply pipe 1 lwhich serves thoroughly to wash the material as it travels up the incline. The upper end of the conveyor is provided in its lower wall with a delivery 'spout 12.

The rate of flow of the acid treated milk, and the dimensions of the serpentine flow r`box 36, and parts of the conveyor 4|, and the effective speed of the conveyor 4|, are such that the grain curd remains in the bath of whey for from ten to twenty minutes. This bathing of the grain curd in the whey is an important feature because it insures that the casein will reach its iso-electric point. I have found that this is very desirable in order to insure againstthe casein containing soluble calcium salts which, if present, would result in the formation of pin holes or brittleness in a. film made from such casein. On the other hand, if lthe caseinremains in the whey for too long a time, it is difficult to wash out all of the whey and thus prevent 'whey sugar contamination. 'Ihe best results, so far as the nal product is concerned, appear to be obtained when the casein 'after drying and milling has an average pH of from 4.63 to 4.67. It is understood that the flow of acid through the acid valve I6 must be in sufficient excess so that there is enough acid in the whey bath to permit the required absorption or penetration of acid into the casein particles, otherwise the finished material after drying. and milling .will not have the required pH value. However, if the nal pH value is below the range specified, it will be necessary to add a supply of mineral acid so as to puce s niiealkali which is undesirable from the standpoint o! brittleness in the nlm to be manufactured or c ast from such casein.

The thoroughly washed grain curd as soon as it is discharged from the delivery spout 12 is dried and milled, i. e. comminuted in the usual manner. The drying may be eected, for example, in a casein tunnel at a progressively increasing temperature until the moisture been reduced to 6% or less.

Changes may be made in the described embodiment without departing from the spirit ot the invention, the scope of which should be determined b'y reference to the follo s clsims, said claims being construed es broadly es possible, consistent with the stste oi the ert.

I claim as my invention: Y

1. The improvement in the ert of seperetins casein from milk which mi; in hosting unpasteurized skim milk by counter dos; ineens so that no portion thereof is rsised shove about 110 F., quickly and intimately mixing with seid :uw

ly divided grained curd. bathing the curd in its whey so as to give time for the scid in the whey 'to penetrate to the interior of the granules ond bring all o the casein to its iso-electric point, but

before there has been :any msteriol suger contamination, then separating the whey rom the curd, washing the curd end drying the eme.

2. The improvement in the srt of .nswuiecturing dry casein, which consists in quickly and intimately mixing together two continuous stre of mineral acid with fresh, (l. e. unpnste) skimmed milk which has been heated to counterflow means to about 110 F. without sny portion of said milk to substantially shove sold temperature so as to produce e. nely divided grained curd, bathing while egitsting the curd in its whey for between ten and twenty minutes so as to give time for the scid in the Whey to penetrste to the interior or the granules and ring ell of the to its iso-electric point,

but before .there has been any material sugar contamination, then immediately separating the whey from the curd, w the curd and dryinsthesamesoastorcducethemoistureto about 6% or less. d

t. The improvement in the artoi manufscturing dry which consists in quickly end intimately mixing together two continuous streams o! mineral acid with fresh., (i. e. un-

teurized) 2 i to about 110 F. by counter-flow means, whereby substantiallynone of said milk has been overheated so as to produce a nely divided ined curd. there being present enough acid to produce a distinctly acid whey condition, bathing while l5 agiteting the curd in its whey so as to give time for the scid in the whey to penetrate to the lnterior of the granules and bring all of the cin to its iso-electric point, but before there has any material sugor connation, then seperst 2@ ins the whey from the curd, was mi' the c wd the www;

s. The improvement in the srt of making c in having a pH of from 4.63 to 4.67, from mili: which consists in quickly end intimately mixing together two continuous streams of mineral scid with fresh, (i. e. unpnsteurized) ed nllis `which hos been heated to ut 110 F. by counter-now mesns, whereby substantially none of sold milk has been over-heated sores to produce s finely divided grained curd,there being errcess of scid so that the resulting whey will be distinctly scid. bathing while sglteting the curd in seid scid `whey for between' ten and twenty minutes so as to give for the scid in the whey to penetrate to the interior of the ules end bring eil of the cesein to its lso-electric point, but before there hos been shy materiel sugercontnstion, then edietely separat ing the whey from the urd. mm1-:f1 the curd end drying the e so es to reduce the moisture to eut 6% or less.

milk which has` been heated l0 

